Represent & Compare Functions MathBitsNotebook.com Terms of Use   Contact Person: Donna Roberts

Functions can be represented in a variety of forms,
such as "descriptions", "tables", "equations" and/or "graphs".

 Function Description:
A function may be represented with a
description of its process.
 "The function will be such that each value entered will be multiplied times two and added to the number one."

 Function Table:

A function may be represented with a table
of the ordered pairs.

A function is shown in the table at the right.
By examining the table, you can see that each y-value
is twice the corresponding x-value plus 1.

 Function Equation:
 A function may be represented with an equation of the form "y =". The equation y = 2x + 1 represents our function. The equation may first appear in a different form such as 2x - y = -1 or 2x - y + 1 = 0. These are all the same equation.

 Function Graph:

A function may be represented
with a
graph.

The graph shows a function whose y-value is twice the x-value plus 1, or y = 2x + 1.

This graph assumes that all Real numbers can be "fed" into this function.
(All Real numbers are the domain.)

Comparing functions expressed in different forms is a popular question.
Given the two linear functions shown below:

Function 1:

 x y 0 1 1 2 2 3 3 4

Function 2:

a) Which function has the larger slope? Function 2

b) Which function has the larger y-intercept? Function 1

y-intercept has an x-value of 0.
y-intercept is 1.

y-intercept is where the graph crosses the y-axis.
y-intercept is -2.

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